RtlUpcaseUnicodeStringToCountedOemString function (ntifs.h)

Article
09/27/2023

The RtlUpcaseUnicodeStringToCountedOemString routine translates a given Unicode source string into an uppercase counted OEM string using the current system OEM code page.

Syntax

NTSYSAPI NTSTATUS RtlUpcaseUnicodeStringToCountedOemString(
       POEM_STRING      DestinationString,
  [in] PCUNICODE_STRING SourceString,
  [in] BOOLEAN          AllocateDestinationString
);

Parameters

DestinationString

Pointer to a caller-allocated buffer to receive the counted OEM string. If AllocateDestinationString is FALSE, the caller must also allocate a buffer for the Buffer member of DestinationString to hold the OEM data. If AllocateDestinationString is TRUE, RtlUpcaseUnicodeStringToCountedOemString allocates a buffer large enough to hold the string, passes a pointer to it in Buffer, and updates the length and maximum length members of DestinationString accordingly.

[in] SourceString

Pointer to the Unicode string to be translated.

[in] AllocateDestinationString

Set to TRUE if RtlUpcaseUnicodeStringToCountedOemString should allocate the buffer space for the DestinationString, FALSE otherwise. If this parameter is TRUE, the caller is responsible for freeing the buffer when it is no longer needed by calling RtlFreeOemString.

Return value

RtlUpcaseUnicodeStringToCountedOemString returns STATUS_SUCCESS if it returns a translated string at DestinationString. Otherwise, no storage was allocated, nor was any conversion performed. It returns STATUS_UNMAPPABLE_CHARACTER if it cannot translate a character in the given SourceString.

Remarks

RtlUpcaseUnicodeStringToCountedOemString returns a string that is not null-terminated. It translates the given source string using the OEM code page that was installed as the current system code page at system boot time, and converts the translated string to uppercase.

To find a best-match mapping for any special characters, such as a copyright character, in the given source string, RtlUpcaseUnicodeStringToCountedOemString performs the following operations:

Translates a copy of the Unicode string at SourceString into an OEM string
Translates the OEM string back into Unicode
Converts this new Unicode string to uppercase
Translates the uppercase Unicode string into a counted OEM string and returns it at DestinationString

This routine does not modify the source string.

For information about other string-handling routines, see Run-Time Library (RTL) Routines.

Requirements

Requirement	Value
Target Platform	Universal
Header	ntifs.h (include Ntifs.h)
Library	NtosKrnl.lib
DLL	NtosKrnl.exe
IRQL	< DISPATCH_LEVEL